The present invention relates to an electronic drum in which the deviation among electric signals which correspond to detected percussions of substantially equal striking force but occurring at different locations on the drum is changed in accordance with a change in striking force, and in which the stick feeling is similar to that in an acoustic drum.
In a conventional electronic drum, a player strikes a drumhead with drumsticks, and vibrations generated by this striking are converted to electrical signals. A PCM (Pulse Coded Modulation) sound source memorizing a real sound waveshape of the drum or such a rhythm sound source as constructed by, for example, an FM (Frequency Modulation) sound source is drived in accordance with striking information representing striking time, volume and so on. Thereby, an electronic drum sound is sounded from at a loudspeaker. The following demands have arisen for an electronic drum: (1) uniform outputs (sensitivity) of a pickup irrespective of striking positions if struck by same striking force; (2) changes in magnitude of output signals in accordance with the different magnitudes of striking force for a player's musical expression; and (3) drumstick feeling similar to that of an acoustic drum.
However, in a conventional electronic drum, a piezoelectric element is directly mounted on or under a wood or plastic plate corresponding to a drumhead to convert a mechanical vibration of the plate to an electrical signal, so that the above demand (1) can be satisfied. However, since the wood or plastic plate which a player must strike is a hard, drumstick feeling greatly differs from that of an acoustic drum. In order to improve drumstick feeling, rubber or the like is adhered to the upper surface of the hard board, but sensitivity is degraded, resulting in inconvenience.
Another conventional electronic drum is also known, as shown in FIG. 1. A drumhead 1 is set on a body 2. A cushion member 4 is disposed between the drumhead 1 and an intermediate board 3. A dynamic loudspeaker 5 is mounted as a microphone on the lower surface of the intermediate board 3. In such an electronic drum, stick feeling can be similar to that of an acoustic drum. However, light stick work cannot be accurately picked up. In addition, since the loudspeaker 5 has a large thickness, a total thickness of the drum is increased, resulting in inconvenience.